Cellulose acetate composition of matter containing salicyl aldehyde



Patented May 17, 1932 UNITED STATES PATENT OFFICE. J

HENRY B. SMITH, OF ROCHESTER, NEW YORK, ASSIGNOB TO EASTMAN KODAK COM-PANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK CELLULOSEACETATE COMPOSITION OF MATTER CONTAINING SALICYL ALDEHYDE No Drawing.

This invention relates to cellulose acetate compositions, and moreparticularly to compositions containing cellulose acetate and aplasticizer in such a proport1on as will give to the product very highflexibility.

The addition of plasticizers to cellulose acetate for inducingflexibility in the product with which the plasticizer is incorporatedhas, of course, been practiced for decades, and the plasticizerhereinafter mentioned has even been employed with cellulose acetate 1nsmall proportions. However, the flexiblllty of a sheet made from such acomposition of matter, for instance such as photographic film base, issuch as permits the sheet to be bent several times, but the sheet haslittle extensibility and without the use of heat or solvents to softenit it will not conform readily, for instance, to an irregular surface orshape as may well be desired for certain uses.

No one has to my knowledge heretofore incorporated with celluloseacetate the plasticizer herein named in amounts approximate- 1y equal tothe weight of the cellulose acetate employed, or in other words,approximately 100% of the plasticizer based upon the weight of thecellulose acetate, in order to obtain a more flexible product than thatreferred to above. Furthermore, it was entirely unexpected that onecould incorporate as much as 100% of this plasticizer in a celluloseacetate composition, for the reason that many plasticizers have beenfound to be incompatible with cellulose acetate in amounts in excess of50% and frequently in amounts as low as 30% or even 10%; the addition ofmore than these percentages of the plasticizer merely resulted in theplasticizer crystallizing out, the solution gelling, the productbecoming hazy or opaque, or otherwise becoming useless.

I have found that, upon the addition to cellulose acetate ofapproximately 100% of this plasticizer, quite unexpected compatibilityof the plasticizer with the cellulose acetate exists and also that quiteunexpected flexibility, plasticity and clarity of the final productresults. Such compositions have great utility where a highly flexiblecompound is desired, such as the coating of a base (for instance, clothor other fabric) in the production of Application filed September 15,1931. Serial No. 562,997.

artificial leather or the production of relatively thin sheets whereinmore than the usual flexibility is important. Such a composition, ifconverted, for instance, into sheet form, will be found to be supple andnon-rigid, and to have the'ability to conform readily to a surface uponwhich it may be-placed, and this even at atmospheric temperatures. 1

It is among the objects of my invention, therefore, to produce acomposition of matter containing cellulose acetate which has a highdegree of flexibility, plasticity, extensibility and clarity. It is afurtherobject of my invention to employ a certain plasticizer in proportions much higher than heretofore attempted. Another object of myinvention is to prepare artificial leather by coating a celluloseacetate-plasticizer composition upon a. fabric or other base.

I have found that it is possible to incor- I porate with 100 parts ofcellulose acetate approx mately 100 parts (or in other wordsapproxlmately 100%) of salicyl aldehyde, which has the structuralformula CHO This novel composition of matter is produced by merelymixing the plasticizer with cellulose acetate and then adding suficientof a common solvent, such as acetone (assuming acetone-soluble celluloseacetate is employed), whereupon an intimate mixture of the plasticizerwith the cellulose acetate results. The amount of acetone or othercommon solvent to be employed varies, of course, within rather widelimits depending upon the fluidity of the composition desired. 100 partsof acetone will suffice for many purposes, although I prefer to use 400parts. Various high boilers or evaporation retardents, such as ethyllactate, amyl acetate or the like may also be added ifdesired, as iswell known in this art.

The composition of 'matter so produced may then be coated into sheets inthe usual way by depositing it upon plates or rolls and permitting thesolvent to evaporate. If my novel composition is to be employed in themanufacture of artificial leather, it may be coated upon, for instance,a cloth support and the solvent permitted to evaporate, or the clothsupport may be caused to pass through the cellulose acetate plasticizercomposition and permitted to absorb the solution, the solvent in thecoating being then permitted to evaporate, In either case, the solventmay,

ofcourse, be recovered if desired by condensing the vapors, etc.

While above and in the claims appended hereto, I have referred to theuse of a. plasticizer in approximately equal proportions, namely in aratio of approximately 100%, it will be understood that Within thisterminology variations of from to less than 100% of plasticizer and asmuch as to more than of the plasticizer may, in some instances, bedesirable.

Thus it will be observed that I have described a method for thepreparation of a product containing cellulose acetate, which product ispossessed of unusual flexibility and which is very desirable for use inthe production of highly flexible cellulose derivative sheeting or otherarticles of manufacture and which composition is particularly useful inthe production of artificial leather by the coating or impregnation of asupport, such as cloth, with my novel composition of matter. Other usesfor this composition of matter will suggest themselves to those skilledin the various plastic arts.

What I claim as my invention and desire tobe secured by Letters Patentof the United States is 1. A composition of matter comprising celluloseacetate and approximately an equal amount of salicyl aldehyde.

2. A coated textile which comprises a fabric base coated Wit-h acomposition of matter comprising cellulose acetate and approximately anequal amount of salicyl aldehyde.

Signed at Rochester, New York, this 9th day of September, 1931.

HENRY B. SMITH.

